Catheter technology is widely utilized to diagnose many abnormalities, to treat vascular disease, to perform vascular interventions, to deliver devices to occlude vessels, and to focally deliver agents to tissues, among other uses. The catheter technology employed will vary depending on the surgical procedure and the nature and extent of the injury. For a general background on catheter technology and some of the tools and apparatus used involving catheters, see U.S. Pat. No. 5,910,150 issued to Saadat on Jun. 8, 1999 (“Saadat”), the entire disclosure of which is incorporated herein by reference in its entirety. In addition, further background on catheter technology and some of the tools and apparatus used involving catheters is found in U.S. Pat. No. 7,241,257 issued to Ainsworth et al. on Jul. 10, 2007 (“Ainsworth”), the entire disclosure of which is incorporated herein by reference in its entirety.
Some attempts have been made to develop catheters useful and adaptable for multiple applications, see U.S. Pat. No. 5,632,754 issued to Farley et al. on May 27, 1997 (“Farley”), the entire disclosure of which is incorporated herein by reference in its entirety.
Many times the stability of the catheter tip is not problematic or critical to the procedure, but routinely the stability of the catheter tip is indeed important to the success of the particular procedure. In many cases a “guide” catheter is inserted and the tip is placed within or near the orifice of the vessel intended to be treated. See for example U.S. Pat. No. 5,947,995 issued to Samuels on Sep. 7, 1999 (“Samuels”), the entire disclosure of which is incorporated herein by reference in its entirety.
The interventional device catheter of choice, whether it is an angioplasty balloon catheter, a stent delivery device, an atherectomy device, or some other specialized catheters, is then placed coaxially through the guide catheter to effect the desired intervention. In the case of coronary angioplasty, stent placement, or other intervention, the guide catheter frequently “backs out” of the coronary orifice when a guide wire or the interventional device catheter is advanced through the narrowed lesion, or attempts are made to advance through the narrowed lesion, because of the resistance caused by the lesion. For a general background on stenting and guiding catheters, see U.S. Pat. No. 7,645,296 issued to Theron et al. on Jan. 12, 2010 (“Theron”), the entire disclosure of which is incorporated herein by reference in its entirety.
This results in repeated attempts to cross the lesion, change the catheter/guide wires, predilation with a smaller catheter, reinsertion of the original catheter, and so forth, and adds additional risk and cost to the procedure. In the case of chronic total occlusions (CTO's), the crossing of the CTO can be extremely difficult as there is a complete occlusion without a lumen that provides resistance to the passage of the guide wire and interventional device. Moreover, since there is no lumen in CTO's, there is a need to center the lumen of the catheter within the lumen of the vessel to lessen the chance of subintimal dissections by the guide wire. In other words, an eccentrically positioned guide wire has a greater chance of tracking subintimally along the outer circumference of a vascular lumen than does a guide wire positioned centrally within the lumen.
Similarly, in the endovascular treatment of carotid artery lesions, the acute angles, especially at the origin of the left common carotid artery, create difficulty in advancing the stent delivery catheters as the guide catheters tend to back out of the orifice when the stent delivery catheters are advanced.
This results in repeated attempts at positioning the catheters, changing the catheters, and added risk and cost to the procedure. The risk of stroke increases with the difficulty of the procedure.
In fact, the same type of problem occurs with regularity anywhere in the body in which a catheter or guide wire is attempted to be pushed through a tight stenosis. The resistance of the stenotic lesion, along with the curvature of the arteries, prevent enough forward force or “pushability” to advance the interventional devices through the lesion easily. Most vascular catheterizations are done with a percutaneous approach through the femoral artery or vein. As will be shown, in the arterial system, the catheters must then take a circuitous route through the aortic arch to access most any vessel supplying the head and neck, upper extremity, and the heart. The vessels in the abdomen branch in an acute angle (with respect to the femoral approach) making them difficult to access also. While the vessels of the lower extremity may be approached with an antegrade puncture in the ipsilateral femoral artery, accessing and treating them may present similar problems as above if the access is done from the contralateral femoral artery. In sum, there is very infrequently a vessel that is subjected to an endovascular intervention of any type in which there is a more or less straight line of force to place and advance the catheter tip from the femoral access point. The resulting forces are frequently not in the direction of the catheter tip, causing the catheter tip's purchase within the selected vessel to be tenuous, especially since the heart is contracting and the aorta is pulsating. The combination of the tortuous path the catheters must take, the resistance within the vessel caused by vessel tortuosity or the constricted lesion, and the pulsations of the heart and the aorta combine to make vascular interventions more difficult, more costly, and more risky to the patient than is generally perceived.
Different catheter shapes and configurations have been developed to access problematic arteries, but frequently the choice of a specialized shape is made only after repeated attempts to catheterize an artery or to perform an intervention within an artery have failed. Sometimes a shape is chosen which is successful in catheterizing an artery, but the interventional device cannot be passed through the catheter or guide catheter to the lesion without dislodging the guide catheter. Pushing the inner catheter against tortuous vessels or a tight stenotic lesion essentially pushes the guide catheter out of the orifice of the vessel. The difficulties described above in the current procedures and devices are overcome, as discussed, by changing out the catheters, using other methods and devices, albeit at increased cost and risk, to achieve the desired result.
In other interventions, substances or devices are injected or delivered into certain arteries in which it is critical that the catheter tip is stable and there is no movement at all, less the patient may suffer serious and even fatal sequalae. One of these vascular interventions involves infusing concentrated chemotherapeutic agents directly into an artery supplying an organ to treat tumors within that organ. The following description involves placing a catheter in the hepatic artery and serves as an example of the problems associating with delivering a substance or device into arteries.
There are several methods of treating cancerous tumors including surgery, chemotherapy, focal ablation by delivery of various forms of energy, radiation, among others. Often, tumors are not resectable by surgery because they have spread into the surrounding tissue or to distant tissue, such as the liver, lung, or brain. The treatment of metastatic disease to these organs is done with chemotherapy, focal surgical resection, focal ablation and occasionally radiation when there are only a few lesions. Oftentimes, the metastatic disease is diffused and not amenable to surgery, radiation or focal ablation. This leaves chemotherapy as the only alternative, and the effectiveness of the intravenous chemotherapy is limited by the systemic toxicities caused by the drug, including bone marrow suppression, neutropenia, nausea, diarrhea, anorexia, wasting, cachexia, bacterial or viral overgrowth among others.
Often perfusion of the organ containing the tumor or tumors with a chemotherapeutic agent is performed. This may be done by simply injecting the chemotherapeutic agent directly into the artery supplying the organ, or by chemoembolization in which the chemotherapeutic agent is mixed with or attached to some substance before it is injected. The injection may be made into a branch artery that supplies the targeted tumor rather than in the main artery to the organ. This has been referred to as selective chemoembolization. Substances mixed with or attached to the chemotherapeutic agent include gelfoam, lipiodal, and other substances. The chemotherapeutic agent may be coated on small beads that are embolized to the tumor as drug eluting beads (DEB's.) The beads that are embolized may instead carry a radioactive substance, such as Yttrium 90, a beta emitter. Collectively, methods and substances that combine radiation or chemotherapeutic agents with a carrier are termed “embolics.” The selective injection into the branch artery supplying the tumor insures the embolization of the beads, containing either chemotherapeutic agent or a radioactive agent, to the tumor bed where the beads lodge in small arterioles and the substance attached to the beads acts upon the tumor over several days to weeks rather than the rather passive non-selective method of just injecting a chemotherapeutic agent into the artery which creates only a fleeting contact with the tumor. When the embolics are injected into an artery, they will eventually occlude the arterial branches and the artery, causing diminished to stagnant flow in the artery. In this case, there is a likelihood of reflux of the emoblics out of the intended artery causing them to embolize to other unintended arteries and organs. This may cause a litany of problems and complications, obviously. It is a purpose of the current invention to direct the chemotherapeutic agent or radioactive agent with or without embolics toward the target tumor or organ, to stabilize the catheter tip in appropriate position and to prevent reflux of the agents out of the intended vessel. Moreover, by controlling the flow through the current invention and the pressure distal to the tip of the device, the pressure distally can be kept lower than pressure proximally obviating any reflux.
A system, process, and method of isolated perfusion of organs with a very high dose of a chemotherapeutic agent, collection of the effluent venous blood from that organ before it enters the systemic circulation, filtering the chemotherapeutic agent from the collected blood, and returning the filtered blood without the chemotherapeutic agent to the systemic circulation has been described and has shown great effectiveness to date in treating tumors of the liver. In essence, a very high dose of a chemotherapeutic agent is infused into the hepatic artery over a period of time, usually from 30 minutes to an hour. The high dose chemotherapeutic agent perfuses the liver and is much more effective than a traditional systemic dose administered intravenously. This drug is taken up by the tumor and the remainder flows into the hepatic veins, which are a series of veins that drain from the liver into the upper inferior vena cava (IVC.) This blood which still contains toxic levels of the chemotherapeutic agent is collected by an isolation device which is part of this special apparatus. The hepatic infusion catheter which is placed percutaneously is usually a standard angiographic catheter. The hepatic venous blood isolation device is a double balloon system that is deployed in the inferior vena cava, the balloons being inflated above and below the hepatic veins, the hepatic venous effluent collected into a catheter and pumped through a filter outside the body that removes the chemotherapeutic agent, and returns to the superior vena cava via another catheter. A through lumen is provided to allow blood from the inferior vena cava to flow back to the heart while the balloons are occluding the vena cava.
While current devices are generally effective in treating the tumor or tumors of the liver, they are somewhat crude and cumbersome to use, as there sometimes is reflux of the toxic chemotherapeutic agent out of the hepatic artery and into arteries supplying the bowel, and the catheter tip may become dislodged from its place in the proper hepatic artery, retracting more proximally and infusing agent into arteries supplying the proximal small bowel, pancreas, spleen, and other organs. This is of great importance as the dose being infused may be up to ten times the usual intravenous dose, and hence can cause serious side effects if not collected as above before entering the systemic circulation. If it is not infused into the correct artery, it will not be collected by the venous recovery device, and this concentrated toxic substance will essentially be a local and systemic poison with which the body is unable to deal. Infusion catheters with a balloon on the distal end have been described, but the balloon must be expanded completely to produce stability of the distal catheter and, in doing so, obstructs the flow of the vessel and the flow of the infused material. While the current invention is described for infusion of a chemotherapeutic agent into the liver, it should be realized that the current invention could be utilized in other organs and regions of the body to infuse any number of medicines, substances, agents, particles, occlusive devices, stents, coils, and so forth in those different regions.
Furthermore, in perfusing the liver, the standard angiographic catheter which is placed in the hepatic artery usually is inserted via a femoral approach, traverses the iliac artery and abdominal aorta and then must be placed in the celiac axis which is frequently at a 135 degree or greater angle to the aorta, advanced further into the common hepatic artery, and finally placed with the tip in the proper hepatic artery which is a rather short artery. This tortuous path places some torque on the catheter, and patient motion, whether voluntary or from normal respiration or vascular pulsations, may cause the catheter tip to back out of the proper hepatic artery during the infusion of the chemotherapeutic agent. This causes the toxic chemotherapeutic agent to flow into vessels other than the intended ones, potentially damaging those tissues supplied by theses vessels, including the pancreas, duodenum, stomach, and spleen among others. Even if the catheter tip does not move and is stable, there is the possibility of reflux of the toxic agent out of the hepatic artery and into these adjacent arteries as spasm may develop in the hepatic arteries as a result of the infusion of the chemotherapeutic agent, or the infusion rate may exceed the flow in the hepatic artery for some other reason resulting in the volume being infused exceeding the capacity of the artery. The infused agent then refluxes out of the intended artery and into the surrounding vessels not intended for infusion causing the problems discussed above and even death. While the majority of cases of infusions may well be successful with the current prior art device, even a small minority of the infusion procedures that have complications would give the clinical oncologists and oncological surgeons who care for these patients concern and raise questions as to whether the procedure is truly safe. This doubt may prevent thousands, and potentially hundreds of thousands, of patients that may benefit from this therapy from receiving it and prolonging their lives.
Additionally, in the case of renal cell carcinoma, it is frequently advantageous to embolize coils or other materials into the renal artery before a nephrectomy. This creates a more or less bloodless field for the surgeon and makes the operation easier, safer, and quicker. It involves placing a catheter in the renal artery and delivering a special coil or other material to occlude the renal artery. The procedure is usually straightforward. In some cases, however, the catheter tip becomes dislodged, usually while attempting to place the second or third coil in the renal artery and the coil embolizes down the aorta and into a lower extremity or other vessel where it must be retrieved by catheters or by surgery. This is another example of catheter tip instability causing an iatrogenic complication.
In crossing a chronic total occlusion, sometimes there is a need to approach the lesion retrograde, or from a downstream location. Frequently the distal aspect of the CTO is easier to enter than the proximal arterial cap for several reasons. In this maneuver, the guide wire is passed from distally in a retrograde manner through the CTO and then the tip of the guide wire is captured by a snare inserted in a standard antegrade manner and then withdrawn through an antegrade catheter. This maneuver includes engaging the guide wire with the snare, then placing traction on the snare dragging the guide wire into the antegrade catheter and then out the external end of the antegrade catheter. When this is done, the guide wire is usually deformed and bent upon itself. This provides the operator with access that would otherwise not be possible. The current device placed antegrade upstream of the occlusion, with its funnel shape, could be utilized as a capture device to capture the guide wire placed in a retrograde manner through the occlusion. This may be important when the guide wire cannot be captured by a snare, bent on itself and easily fished out through the standard antegrade catheter. Additional uses of the current invention include capture of guide wires in any artery or vein, channel of the body, or tract or space, whether natural or surgically created.
Traditional catheter techniques or technologies to prevent or inhibit instability of a catheter as positioned within a patient can impart trauma to the patient and/or prevent or severely restrict blood flow.
For example, U.S. Pat. No. 5,078,685 issued to Colliver on Jan. 7, 1992 (“Colliver”) provides a vascular catheter with an elongated, flexible tubular catheter body fitted with a rigid tunnel member. The tunnel member is intended to define an open, non-collapsible, longitudinal passageway for blood flow outside of the catheter body when the vascular catheter is inserted in a blood vessel of a patient. However, such a rigid collar-like member enables only imprecise degrees of pressure to be axially imparted to the blood vessel, thereby causing unnecessary trauma to the patient.
U.S. Pat. No. 6,238,412 issued to Dubrul et al. on May 29, 2001 (“Dubrul I”), and U.S. Pat. No. 6,695,858 issued to Dubrul et al. on Feb. 24, 2004 (“Dubrul II”), describe a catheter device for removal of a blockage in a passageway such as a dialysis graft or in a body passageway. The device of Dubrul I and II includes a traditional funnel-like catheter for reception and aspiration of the blockage and an occlusion engaging element supported on a wire that extends through the catheter. The device includes a braid device that expands against the blood vessel wall to stabilize the catheter and to prevent the occlusion from passing around the outside of the device; blood flow is also prevented from passing through the device.
U.S. Pat. No. 6,699,260 issued to Dubrul et al. on Mar. 2, 2004 (“Dubrul III”) describes a catheter device for removal of a blockage in a body passageway fitted with a multi-wing malecot expansion device. Similar to Dubrul I and II, the Dubrul III device entirely blocks blood flow, and the targeted blockage, from passing around or through the device. Further, U.S. Pat. Pub. No. 2010/0114113 to Dubrul et al. published May 6, 2010 (“Dubrul IV”) discloses a catheter device for occlusion removal that blocks blood flow.
U.S. Pat. Pub. No. 2004/0260333 to Dubrul et al. published on Dec. 23, 2004 (“Dubrul V”) and U.S. Pat. Pub. No. 2010/0030256 to Dubrul et al. published on Feb. 4, 2010 (“Dubrul VI”) describe a collection of funnel catheters, catheter/dilator assemblies, occluders, and associated methods which either entirely block blood flow or do not allow a controlled, predictable adjustment of allowed blood flow.
The prior art catheters and methods of use do not provide a minimal-trauma device that enables predictable and adjustable blood flow through or around a catheter device, prevent reflux as desired, allow centered and/or directional flow of medicament, or accurate, reliable and stable precise positioning. The device and method of the current invention described below addresses these deficiencies and problems, and further solves the problem of catheter tip instability which may result in infusion of a toxic agent unintentionally into surrounding vessels while preventing reflux from the desired vessel into the surrounding vessels and tissues even when the catheter tip is stable and other factors cause the toxic substance to reflux.